Urge for sex almost always fatal for small male spiders

Washington, Sept 11 : Researchers from Miami University in Ohio have found that how small male spiders are relative to females has a large effect on the frequency of sexual cannibalism.

Female spiders are voracious predators and consume a wide range of prey, which sometimes includes their mates.

Now, researchers Shawn Wilder and Ann Rypstra from Miami University in Ohio have found that males are more likely to be eaten if they are much smaller than females, which likely affects how easy they are to catch.

During their research, they found that in one species of spider, Hogna helluo, large males were never consumed while small males were consumed 80 percent of the time.

This result was also confirmed when Wilder and Rypstra examined published data from a wide range of spider species.

Males are more likely to be eaten in species where males are small relative to females.

Much research on sexual cannibalism has focused on a few extreme cases involving sexual selection and sperm competition.

However, by looking at data on a wide range of spiders, Wilder and Rypstra found that the size of the male relative to the female determines how often sexual cannibalism occurs in a species.

"We were surprised to find that such a simple characteristic such as how small males are relative to females has such a large effect on the frequency of sexual cannibalism," said Shawn Wilder.

The study is published in the September issue of the American Naturalist.